Hans Christian Andersen's Little Mermaid (1846) is a literary fairy tale about a mermaid who wants to become a human being. The transformation has a great price. In The Changeling Sea McKillip has created a mer-prince who wants to become a merman, a human prince who is a sea dragon but eventually wants to become a human prince, and a girl who wants to become a fully human adult capable of loving and being loved for herself. All these transformations eventually take place for McKillip's characters.

There are many other tales involving sea creatures and humans. Often the transformations cause disastrous results and the mer-people usually return to their undersea world. Jane Yolen's Greyling: A Picture Story from the Islands of Shetland (1968) is a recent tale of a selchie or seal boy raised by a human who reverts to his seal-form.